Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
[deliverable/linux.git] / arch / x86 / Kconfig
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH != "i386"
5 ---help---
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9 config X86_32
10 def_bool y
11 depends on !64BIT
12 select CLKSRC_I8253
13 select HAVE_UID16
14
15 config X86_64
16 def_bool y
17 depends on 64BIT
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
20
21 ### Arch settings
22 config X86
23 def_bool y
24 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
26 select ARCH_HAS_FAST_MULTIPLIER
27 select ARCH_MIGHT_HAVE_PC_PARPORT
28 select ARCH_MIGHT_HAVE_PC_SERIO
29 select HAVE_AOUT if X86_32
30 select HAVE_UNSTABLE_SCHED_CLOCK
31 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
32 select ARCH_SUPPORTS_INT128 if X86_64
33 select HAVE_IDE
34 select HAVE_OPROFILE
35 select HAVE_PCSPKR_PLATFORM
36 select HAVE_PERF_EVENTS
37 select HAVE_IOREMAP_PROT
38 select HAVE_KPROBES
39 select HAVE_MEMBLOCK
40 select HAVE_MEMBLOCK_NODE_MAP
41 select ARCH_DISCARD_MEMBLOCK
42 select ARCH_WANT_OPTIONAL_GPIOLIB
43 select ARCH_WANT_FRAME_POINTERS
44 select HAVE_DMA_ATTRS
45 select HAVE_DMA_CONTIGUOUS
46 select HAVE_KRETPROBES
47 select GENERIC_EARLY_IOREMAP
48 select HAVE_OPTPROBES
49 select HAVE_KPROBES_ON_FTRACE
50 select HAVE_FTRACE_MCOUNT_RECORD
51 select HAVE_FENTRY if X86_64
52 select HAVE_C_RECORDMCOUNT
53 select HAVE_DYNAMIC_FTRACE
54 select HAVE_DYNAMIC_FTRACE_WITH_REGS
55 select HAVE_FUNCTION_TRACER
56 select HAVE_FUNCTION_GRAPH_TRACER
57 select HAVE_FUNCTION_GRAPH_FP_TEST
58 select HAVE_SYSCALL_TRACEPOINTS
59 select SYSCTL_EXCEPTION_TRACE
60 select HAVE_KVM
61 select HAVE_ARCH_KGDB
62 select HAVE_ARCH_TRACEHOOK
63 select HAVE_GENERIC_DMA_COHERENT if X86_32
64 select HAVE_EFFICIENT_UNALIGNED_ACCESS
65 select USER_STACKTRACE_SUPPORT
66 select HAVE_REGS_AND_STACK_ACCESS_API
67 select HAVE_DMA_API_DEBUG
68 select HAVE_KERNEL_GZIP
69 select HAVE_KERNEL_BZIP2
70 select HAVE_KERNEL_LZMA
71 select HAVE_KERNEL_XZ
72 select HAVE_KERNEL_LZO
73 select HAVE_KERNEL_LZ4
74 select HAVE_HW_BREAKPOINT
75 select HAVE_MIXED_BREAKPOINTS_REGS
76 select PERF_EVENTS
77 select HAVE_PERF_EVENTS_NMI
78 select HAVE_PERF_REGS
79 select HAVE_PERF_USER_STACK_DUMP
80 select HAVE_DEBUG_KMEMLEAK
81 select ANON_INODES
82 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
83 select HAVE_CMPXCHG_LOCAL
84 select HAVE_CMPXCHG_DOUBLE
85 select HAVE_ARCH_KMEMCHECK
86 select HAVE_USER_RETURN_NOTIFIER
87 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
88 select HAVE_ARCH_JUMP_LABEL
89 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90 select SPARSE_IRQ
91 select GENERIC_FIND_FIRST_BIT
92 select GENERIC_IRQ_PROBE
93 select GENERIC_PENDING_IRQ if SMP
94 select GENERIC_IRQ_SHOW
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select IRQ_FORCED_THREADING
97 select HAVE_BPF_JIT if X86_64
98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select ARCH_HAS_SG_CHAIN
100 select CLKEVT_I8253
101 select ARCH_HAVE_NMI_SAFE_CMPXCHG
102 select GENERIC_IOMAP
103 select DCACHE_WORD_ACCESS
104 select GENERIC_SMP_IDLE_THREAD
105 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
106 select HAVE_ARCH_SECCOMP_FILTER
107 select BUILDTIME_EXTABLE_SORT
108 select GENERIC_CMOS_UPDATE
109 select HAVE_ARCH_SOFT_DIRTY if X86_64
110 select CLOCKSOURCE_WATCHDOG
111 select GENERIC_CLOCKEVENTS
112 select ARCH_CLOCKSOURCE_DATA
113 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
114 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
115 select GENERIC_TIME_VSYSCALL
116 select GENERIC_STRNCPY_FROM_USER
117 select GENERIC_STRNLEN_USER
118 select HAVE_CONTEXT_TRACKING if X86_64
119 select HAVE_IRQ_TIME_ACCOUNTING
120 select VIRT_TO_BUS
121 select MODULES_USE_ELF_REL if X86_32
122 select MODULES_USE_ELF_RELA if X86_64
123 select CLONE_BACKWARDS if X86_32
124 select ARCH_USE_BUILTIN_BSWAP
125 select ARCH_USE_QUEUE_RWLOCK
126 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
127 select OLD_SIGACTION if X86_32
128 select COMPAT_OLD_SIGACTION if IA32_EMULATION
129 select RTC_LIB
130 select HAVE_DEBUG_STACKOVERFLOW
131 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
132 select HAVE_CC_STACKPROTECTOR
133 select GENERIC_CPU_AUTOPROBE
134 select HAVE_ARCH_AUDITSYSCALL
135 select ARCH_SUPPORTS_ATOMIC_RMW
136 select HAVE_ACPI_APEI if ACPI
137 select HAVE_ACPI_APEI_NMI if ACPI
138 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
139 select X86_FEATURE_NAMES if PROC_FS
140
141 config INSTRUCTION_DECODER
142 def_bool y
143 depends on KPROBES || PERF_EVENTS || UPROBES
144
145 config PERF_EVENTS_INTEL_UNCORE
146 def_bool y
147 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
148
149 config OUTPUT_FORMAT
150 string
151 default "elf32-i386" if X86_32
152 default "elf64-x86-64" if X86_64
153
154 config ARCH_DEFCONFIG
155 string
156 default "arch/x86/configs/i386_defconfig" if X86_32
157 default "arch/x86/configs/x86_64_defconfig" if X86_64
158
159 config LOCKDEP_SUPPORT
160 def_bool y
161
162 config STACKTRACE_SUPPORT
163 def_bool y
164
165 config HAVE_LATENCYTOP_SUPPORT
166 def_bool y
167
168 config MMU
169 def_bool y
170
171 config SBUS
172 bool
173
174 config NEED_DMA_MAP_STATE
175 def_bool y
176 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
177
178 config NEED_SG_DMA_LENGTH
179 def_bool y
180
181 config GENERIC_ISA_DMA
182 def_bool y
183 depends on ISA_DMA_API
184
185 config GENERIC_BUG
186 def_bool y
187 depends on BUG
188 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
189
190 config GENERIC_BUG_RELATIVE_POINTERS
191 bool
192
193 config GENERIC_HWEIGHT
194 def_bool y
195
196 config ARCH_MAY_HAVE_PC_FDC
197 def_bool y
198 depends on ISA_DMA_API
199
200 config RWSEM_XCHGADD_ALGORITHM
201 def_bool y
202
203 config GENERIC_CALIBRATE_DELAY
204 def_bool y
205
206 config ARCH_HAS_CPU_RELAX
207 def_bool y
208
209 config ARCH_HAS_CACHE_LINE_SIZE
210 def_bool y
211
212 config HAVE_SETUP_PER_CPU_AREA
213 def_bool y
214
215 config NEED_PER_CPU_EMBED_FIRST_CHUNK
216 def_bool y
217
218 config NEED_PER_CPU_PAGE_FIRST_CHUNK
219 def_bool y
220
221 config ARCH_HIBERNATION_POSSIBLE
222 def_bool y
223
224 config ARCH_SUSPEND_POSSIBLE
225 def_bool y
226
227 config ARCH_WANT_HUGE_PMD_SHARE
228 def_bool y
229
230 config ARCH_WANT_GENERAL_HUGETLB
231 def_bool y
232
233 config ZONE_DMA32
234 bool
235 default X86_64
236
237 config AUDIT_ARCH
238 bool
239 default X86_64
240
241 config ARCH_SUPPORTS_OPTIMIZED_INLINING
242 def_bool y
243
244 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
245 def_bool y
246
247 config HAVE_INTEL_TXT
248 def_bool y
249 depends on INTEL_IOMMU && ACPI
250
251 config X86_32_SMP
252 def_bool y
253 depends on X86_32 && SMP
254
255 config X86_64_SMP
256 def_bool y
257 depends on X86_64 && SMP
258
259 config X86_HT
260 def_bool y
261 depends on SMP
262
263 config X86_32_LAZY_GS
264 def_bool y
265 depends on X86_32 && !CC_STACKPROTECTOR
266
267 config ARCH_HWEIGHT_CFLAGS
268 string
269 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
270 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
271
272 config ARCH_SUPPORTS_UPROBES
273 def_bool y
274
275 config FIX_EARLYCON_MEM
276 def_bool y
277
278 source "init/Kconfig"
279 source "kernel/Kconfig.freezer"
280
281 menu "Processor type and features"
282
283 config ZONE_DMA
284 bool "DMA memory allocation support" if EXPERT
285 default y
286 help
287 DMA memory allocation support allows devices with less than 32-bit
288 addressing to allocate within the first 16MB of address space.
289 Disable if no such devices will be used.
290
291 If unsure, say Y.
292
293 config SMP
294 bool "Symmetric multi-processing support"
295 ---help---
296 This enables support for systems with more than one CPU. If you have
297 a system with only one CPU, say N. If you have a system with more
298 than one CPU, say Y.
299
300 If you say N here, the kernel will run on uni- and multiprocessor
301 machines, but will use only one CPU of a multiprocessor machine. If
302 you say Y here, the kernel will run on many, but not all,
303 uniprocessor machines. On a uniprocessor machine, the kernel
304 will run faster if you say N here.
305
306 Note that if you say Y here and choose architecture "586" or
307 "Pentium" under "Processor family", the kernel will not work on 486
308 architectures. Similarly, multiprocessor kernels for the "PPro"
309 architecture may not work on all Pentium based boards.
310
311 People using multiprocessor machines who say Y here should also say
312 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
313 Management" code will be disabled if you say Y here.
314
315 See also <file:Documentation/x86/i386/IO-APIC.txt>,
316 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
317 <http://www.tldp.org/docs.html#howto>.
318
319 If you don't know what to do here, say N.
320
321 config X86_FEATURE_NAMES
322 bool "Processor feature human-readable names" if EMBEDDED
323 default y
324 ---help---
325 This option compiles in a table of x86 feature bits and corresponding
326 names. This is required to support /proc/cpuinfo and a few kernel
327 messages. You can disable this to save space, at the expense of
328 making those few kernel messages show numeric feature bits instead.
329
330 If in doubt, say Y.
331
332 config X86_X2APIC
333 bool "Support x2apic"
334 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
335 ---help---
336 This enables x2apic support on CPUs that have this feature.
337
338 This allows 32-bit apic IDs (so it can support very large systems),
339 and accesses the local apic via MSRs not via mmio.
340
341 If you don't know what to do here, say N.
342
343 config X86_MPPARSE
344 bool "Enable MPS table" if ACPI || SFI
345 default y
346 depends on X86_LOCAL_APIC
347 ---help---
348 For old smp systems that do not have proper acpi support. Newer systems
349 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
350
351 config X86_BIGSMP
352 bool "Support for big SMP systems with more than 8 CPUs"
353 depends on X86_32 && SMP
354 ---help---
355 This option is needed for the systems that have more than 8 CPUs
356
357 config GOLDFISH
358 def_bool y
359 depends on X86_GOLDFISH
360
361 if X86_32
362 config X86_EXTENDED_PLATFORM
363 bool "Support for extended (non-PC) x86 platforms"
364 default y
365 ---help---
366 If you disable this option then the kernel will only support
367 standard PC platforms. (which covers the vast majority of
368 systems out there.)
369
370 If you enable this option then you'll be able to select support
371 for the following (non-PC) 32 bit x86 platforms:
372 Goldfish (Android emulator)
373 AMD Elan
374 RDC R-321x SoC
375 SGI 320/540 (Visual Workstation)
376 STA2X11-based (e.g. Northville)
377 Moorestown MID devices
378
379 If you have one of these systems, or if you want to build a
380 generic distribution kernel, say Y here - otherwise say N.
381 endif
382
383 if X86_64
384 config X86_EXTENDED_PLATFORM
385 bool "Support for extended (non-PC) x86 platforms"
386 default y
387 ---help---
388 If you disable this option then the kernel will only support
389 standard PC platforms. (which covers the vast majority of
390 systems out there.)
391
392 If you enable this option then you'll be able to select support
393 for the following (non-PC) 64 bit x86 platforms:
394 Numascale NumaChip
395 ScaleMP vSMP
396 SGI Ultraviolet
397
398 If you have one of these systems, or if you want to build a
399 generic distribution kernel, say Y here - otherwise say N.
400 endif
401 # This is an alphabetically sorted list of 64 bit extended platforms
402 # Please maintain the alphabetic order if and when there are additions
403 config X86_NUMACHIP
404 bool "Numascale NumaChip"
405 depends on X86_64
406 depends on X86_EXTENDED_PLATFORM
407 depends on NUMA
408 depends on SMP
409 depends on X86_X2APIC
410 depends on PCI_MMCONFIG
411 ---help---
412 Adds support for Numascale NumaChip large-SMP systems. Needed to
413 enable more than ~168 cores.
414 If you don't have one of these, you should say N here.
415
416 config X86_VSMP
417 bool "ScaleMP vSMP"
418 select HYPERVISOR_GUEST
419 select PARAVIRT
420 depends on X86_64 && PCI
421 depends on X86_EXTENDED_PLATFORM
422 depends on SMP
423 ---help---
424 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
425 supposed to run on these EM64T-based machines. Only choose this option
426 if you have one of these machines.
427
428 config X86_UV
429 bool "SGI Ultraviolet"
430 depends on X86_64
431 depends on X86_EXTENDED_PLATFORM
432 depends on NUMA
433 depends on X86_X2APIC
434 ---help---
435 This option is needed in order to support SGI Ultraviolet systems.
436 If you don't have one of these, you should say N here.
437
438 # Following is an alphabetically sorted list of 32 bit extended platforms
439 # Please maintain the alphabetic order if and when there are additions
440
441 config X86_GOLDFISH
442 bool "Goldfish (Virtual Platform)"
443 depends on X86_EXTENDED_PLATFORM
444 ---help---
445 Enable support for the Goldfish virtual platform used primarily
446 for Android development. Unless you are building for the Android
447 Goldfish emulator say N here.
448
449 config X86_INTEL_CE
450 bool "CE4100 TV platform"
451 depends on PCI
452 depends on PCI_GODIRECT
453 depends on X86_IO_APIC
454 depends on X86_32
455 depends on X86_EXTENDED_PLATFORM
456 select X86_REBOOTFIXUPS
457 select OF
458 select OF_EARLY_FLATTREE
459 select IRQ_DOMAIN
460 ---help---
461 Select for the Intel CE media processor (CE4100) SOC.
462 This option compiles in support for the CE4100 SOC for settop
463 boxes and media devices.
464
465 config X86_INTEL_MID
466 bool "Intel MID platform support"
467 depends on X86_32
468 depends on X86_EXTENDED_PLATFORM
469 depends on X86_PLATFORM_DEVICES
470 depends on PCI
471 depends on PCI_GOANY
472 depends on X86_IO_APIC
473 select SFI
474 select I2C
475 select DW_APB_TIMER
476 select APB_TIMER
477 select INTEL_SCU_IPC
478 select MFD_INTEL_MSIC
479 ---help---
480 Select to build a kernel capable of supporting Intel MID (Mobile
481 Internet Device) platform systems which do not have the PCI legacy
482 interfaces. If you are building for a PC class system say N here.
483
484 Intel MID platforms are based on an Intel processor and chipset which
485 consume less power than most of the x86 derivatives.
486
487 config X86_INTEL_LPSS
488 bool "Intel Low Power Subsystem Support"
489 depends on ACPI
490 select COMMON_CLK
491 select PINCTRL
492 ---help---
493 Select to build support for Intel Low Power Subsystem such as
494 found on Intel Lynxpoint PCH. Selecting this option enables
495 things like clock tree (common clock framework) and pincontrol
496 which are needed by the LPSS peripheral drivers.
497
498 config IOSF_MBI
499 tristate "Intel SoC IOSF Sideband support for SoC platforms"
500 depends on PCI
501 ---help---
502 This option enables sideband register access support for Intel SoC
503 platforms. On these platforms the IOSF sideband is used in lieu of
504 MSR's for some register accesses, mostly but not limited to thermal
505 and power. Drivers may query the availability of this device to
506 determine if they need the sideband in order to work on these
507 platforms. The sideband is available on the following SoC products.
508 This list is not meant to be exclusive.
509 - BayTrail
510 - Braswell
511 - Quark
512
513 You should say Y if you are running a kernel on one of these SoC's.
514
515 config IOSF_MBI_DEBUG
516 bool "Enable IOSF sideband access through debugfs"
517 depends on IOSF_MBI && DEBUG_FS
518 ---help---
519 Select this option to expose the IOSF sideband access registers (MCR,
520 MDR, MCRX) through debugfs to write and read register information from
521 different units on the SoC. This is most useful for obtaining device
522 state information for debug and analysis. As this is a general access
523 mechanism, users of this option would have specific knowledge of the
524 device they want to access.
525
526 If you don't require the option or are in doubt, say N.
527
528 config X86_RDC321X
529 bool "RDC R-321x SoC"
530 depends on X86_32
531 depends on X86_EXTENDED_PLATFORM
532 select M486
533 select X86_REBOOTFIXUPS
534 ---help---
535 This option is needed for RDC R-321x system-on-chip, also known
536 as R-8610-(G).
537 If you don't have one of these chips, you should say N here.
538
539 config X86_32_NON_STANDARD
540 bool "Support non-standard 32-bit SMP architectures"
541 depends on X86_32 && SMP
542 depends on X86_EXTENDED_PLATFORM
543 ---help---
544 This option compiles in the bigsmp and STA2X11 default
545 subarchitectures. It is intended for a generic binary
546 kernel. If you select them all, kernel will probe it one by
547 one and will fallback to default.
548
549 # Alphabetically sorted list of Non standard 32 bit platforms
550
551 config X86_SUPPORTS_MEMORY_FAILURE
552 def_bool y
553 # MCE code calls memory_failure():
554 depends on X86_MCE
555 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
556 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
557 depends on X86_64 || !SPARSEMEM
558 select ARCH_SUPPORTS_MEMORY_FAILURE
559
560 config STA2X11
561 bool "STA2X11 Companion Chip Support"
562 depends on X86_32_NON_STANDARD && PCI
563 select X86_DEV_DMA_OPS
564 select X86_DMA_REMAP
565 select SWIOTLB
566 select MFD_STA2X11
567 select ARCH_REQUIRE_GPIOLIB
568 default n
569 ---help---
570 This adds support for boards based on the STA2X11 IO-Hub,
571 a.k.a. "ConneXt". The chip is used in place of the standard
572 PC chipset, so all "standard" peripherals are missing. If this
573 option is selected the kernel will still be able to boot on
574 standard PC machines.
575
576 config X86_32_IRIS
577 tristate "Eurobraille/Iris poweroff module"
578 depends on X86_32
579 ---help---
580 The Iris machines from EuroBraille do not have APM or ACPI support
581 to shut themselves down properly. A special I/O sequence is
582 needed to do so, which is what this module does at
583 kernel shutdown.
584
585 This is only for Iris machines from EuroBraille.
586
587 If unused, say N.
588
589 config SCHED_OMIT_FRAME_POINTER
590 def_bool y
591 prompt "Single-depth WCHAN output"
592 depends on X86
593 ---help---
594 Calculate simpler /proc/<PID>/wchan values. If this option
595 is disabled then wchan values will recurse back to the
596 caller function. This provides more accurate wchan values,
597 at the expense of slightly more scheduling overhead.
598
599 If in doubt, say "Y".
600
601 menuconfig HYPERVISOR_GUEST
602 bool "Linux guest support"
603 ---help---
604 Say Y here to enable options for running Linux under various hyper-
605 visors. This option enables basic hypervisor detection and platform
606 setup.
607
608 If you say N, all options in this submenu will be skipped and
609 disabled, and Linux guest support won't be built in.
610
611 if HYPERVISOR_GUEST
612
613 config PARAVIRT
614 bool "Enable paravirtualization code"
615 ---help---
616 This changes the kernel so it can modify itself when it is run
617 under a hypervisor, potentially improving performance significantly
618 over full virtualization. However, when run without a hypervisor
619 the kernel is theoretically slower and slightly larger.
620
621 config PARAVIRT_DEBUG
622 bool "paravirt-ops debugging"
623 depends on PARAVIRT && DEBUG_KERNEL
624 ---help---
625 Enable to debug paravirt_ops internals. Specifically, BUG if
626 a paravirt_op is missing when it is called.
627
628 config PARAVIRT_SPINLOCKS
629 bool "Paravirtualization layer for spinlocks"
630 depends on PARAVIRT && SMP
631 select UNINLINE_SPIN_UNLOCK
632 ---help---
633 Paravirtualized spinlocks allow a pvops backend to replace the
634 spinlock implementation with something virtualization-friendly
635 (for example, block the virtual CPU rather than spinning).
636
637 It has a minimal impact on native kernels and gives a nice performance
638 benefit on paravirtualized KVM / Xen kernels.
639
640 If you are unsure how to answer this question, answer Y.
641
642 source "arch/x86/xen/Kconfig"
643
644 config KVM_GUEST
645 bool "KVM Guest support (including kvmclock)"
646 depends on PARAVIRT
647 select PARAVIRT_CLOCK
648 default y
649 ---help---
650 This option enables various optimizations for running under the KVM
651 hypervisor. It includes a paravirtualized clock, so that instead
652 of relying on a PIT (or probably other) emulation by the
653 underlying device model, the host provides the guest with
654 timing infrastructure such as time of day, and system time
655
656 config KVM_DEBUG_FS
657 bool "Enable debug information for KVM Guests in debugfs"
658 depends on KVM_GUEST && DEBUG_FS
659 default n
660 ---help---
661 This option enables collection of various statistics for KVM guest.
662 Statistics are displayed in debugfs filesystem. Enabling this option
663 may incur significant overhead.
664
665 source "arch/x86/lguest/Kconfig"
666
667 config PARAVIRT_TIME_ACCOUNTING
668 bool "Paravirtual steal time accounting"
669 depends on PARAVIRT
670 default n
671 ---help---
672 Select this option to enable fine granularity task steal time
673 accounting. Time spent executing other tasks in parallel with
674 the current vCPU is discounted from the vCPU power. To account for
675 that, there can be a small performance impact.
676
677 If in doubt, say N here.
678
679 config PARAVIRT_CLOCK
680 bool
681
682 endif #HYPERVISOR_GUEST
683
684 config NO_BOOTMEM
685 def_bool y
686
687 config MEMTEST
688 bool "Memtest"
689 ---help---
690 This option adds a kernel parameter 'memtest', which allows memtest
691 to be set.
692 memtest=0, mean disabled; -- default
693 memtest=1, mean do 1 test pattern;
694 ...
695 memtest=4, mean do 4 test patterns.
696 If you are unsure how to answer this question, answer N.
697
698 source "arch/x86/Kconfig.cpu"
699
700 config HPET_TIMER
701 def_bool X86_64
702 prompt "HPET Timer Support" if X86_32
703 ---help---
704 Use the IA-PC HPET (High Precision Event Timer) to manage
705 time in preference to the PIT and RTC, if a HPET is
706 present.
707 HPET is the next generation timer replacing legacy 8254s.
708 The HPET provides a stable time base on SMP
709 systems, unlike the TSC, but it is more expensive to access,
710 as it is off-chip. You can find the HPET spec at
711 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
712
713 You can safely choose Y here. However, HPET will only be
714 activated if the platform and the BIOS support this feature.
715 Otherwise the 8254 will be used for timing services.
716
717 Choose N to continue using the legacy 8254 timer.
718
719 config HPET_EMULATE_RTC
720 def_bool y
721 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
722
723 config APB_TIMER
724 def_bool y if X86_INTEL_MID
725 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
726 select DW_APB_TIMER
727 depends on X86_INTEL_MID && SFI
728 help
729 APB timer is the replacement for 8254, HPET on X86 MID platforms.
730 The APBT provides a stable time base on SMP
731 systems, unlike the TSC, but it is more expensive to access,
732 as it is off-chip. APB timers are always running regardless of CPU
733 C states, they are used as per CPU clockevent device when possible.
734
735 # Mark as expert because too many people got it wrong.
736 # The code disables itself when not needed.
737 config DMI
738 default y
739 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
740 bool "Enable DMI scanning" if EXPERT
741 ---help---
742 Enabled scanning of DMI to identify machine quirks. Say Y
743 here unless you have verified that your setup is not
744 affected by entries in the DMI blacklist. Required by PNP
745 BIOS code.
746
747 config GART_IOMMU
748 bool "Old AMD GART IOMMU support"
749 select SWIOTLB
750 depends on X86_64 && PCI && AMD_NB
751 ---help---
752 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
753 GART based hardware IOMMUs.
754
755 The GART supports full DMA access for devices with 32-bit access
756 limitations, on systems with more than 3 GB. This is usually needed
757 for USB, sound, many IDE/SATA chipsets and some other devices.
758
759 Newer systems typically have a modern AMD IOMMU, supported via
760 the CONFIG_AMD_IOMMU=y config option.
761
762 In normal configurations this driver is only active when needed:
763 there's more than 3 GB of memory and the system contains a
764 32-bit limited device.
765
766 If unsure, say Y.
767
768 config CALGARY_IOMMU
769 bool "IBM Calgary IOMMU support"
770 select SWIOTLB
771 depends on X86_64 && PCI
772 ---help---
773 Support for hardware IOMMUs in IBM's xSeries x366 and x460
774 systems. Needed to run systems with more than 3GB of memory
775 properly with 32-bit PCI devices that do not support DAC
776 (Double Address Cycle). Calgary also supports bus level
777 isolation, where all DMAs pass through the IOMMU. This
778 prevents them from going anywhere except their intended
779 destination. This catches hard-to-find kernel bugs and
780 mis-behaving drivers and devices that do not use the DMA-API
781 properly to set up their DMA buffers. The IOMMU can be
782 turned off at boot time with the iommu=off parameter.
783 Normally the kernel will make the right choice by itself.
784 If unsure, say Y.
785
786 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
787 def_bool y
788 prompt "Should Calgary be enabled by default?"
789 depends on CALGARY_IOMMU
790 ---help---
791 Should Calgary be enabled by default? if you choose 'y', Calgary
792 will be used (if it exists). If you choose 'n', Calgary will not be
793 used even if it exists. If you choose 'n' and would like to use
794 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
795 If unsure, say Y.
796
797 # need this always selected by IOMMU for the VIA workaround
798 config SWIOTLB
799 def_bool y if X86_64
800 ---help---
801 Support for software bounce buffers used on x86-64 systems
802 which don't have a hardware IOMMU. Using this PCI devices
803 which can only access 32-bits of memory can be used on systems
804 with more than 3 GB of memory.
805 If unsure, say Y.
806
807 config IOMMU_HELPER
808 def_bool y
809 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
810
811 config MAXSMP
812 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
813 depends on X86_64 && SMP && DEBUG_KERNEL
814 select CPUMASK_OFFSTACK
815 ---help---
816 Enable maximum number of CPUS and NUMA Nodes for this architecture.
817 If unsure, say N.
818
819 config NR_CPUS
820 int "Maximum number of CPUs" if SMP && !MAXSMP
821 range 2 8 if SMP && X86_32 && !X86_BIGSMP
822 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
823 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
824 default "1" if !SMP
825 default "8192" if MAXSMP
826 default "32" if SMP && X86_BIGSMP
827 default "8" if SMP
828 ---help---
829 This allows you to specify the maximum number of CPUs which this
830 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
831 supported value is 4096, otherwise the maximum value is 512. The
832 minimum value which makes sense is 2.
833
834 This is purely to save memory - each supported CPU adds
835 approximately eight kilobytes to the kernel image.
836
837 config SCHED_SMT
838 bool "SMT (Hyperthreading) scheduler support"
839 depends on X86_HT
840 ---help---
841 SMT scheduler support improves the CPU scheduler's decision making
842 when dealing with Intel Pentium 4 chips with HyperThreading at a
843 cost of slightly increased overhead in some places. If unsure say
844 N here.
845
846 config SCHED_MC
847 def_bool y
848 prompt "Multi-core scheduler support"
849 depends on X86_HT
850 ---help---
851 Multi-core scheduler support improves the CPU scheduler's decision
852 making when dealing with multi-core CPU chips at a cost of slightly
853 increased overhead in some places. If unsure say N here.
854
855 source "kernel/Kconfig.preempt"
856
857 config X86_UP_APIC
858 bool "Local APIC support on uniprocessors"
859 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
860 ---help---
861 A local APIC (Advanced Programmable Interrupt Controller) is an
862 integrated interrupt controller in the CPU. If you have a single-CPU
863 system which has a processor with a local APIC, you can say Y here to
864 enable and use it. If you say Y here even though your machine doesn't
865 have a local APIC, then the kernel will still run with no slowdown at
866 all. The local APIC supports CPU-generated self-interrupts (timer,
867 performance counters), and the NMI watchdog which detects hard
868 lockups.
869
870 config X86_UP_IOAPIC
871 bool "IO-APIC support on uniprocessors"
872 depends on X86_UP_APIC
873 ---help---
874 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
875 SMP-capable replacement for PC-style interrupt controllers. Most
876 SMP systems and many recent uniprocessor systems have one.
877
878 If you have a single-CPU system with an IO-APIC, you can say Y here
879 to use it. If you say Y here even though your machine doesn't have
880 an IO-APIC, then the kernel will still run with no slowdown at all.
881
882 config X86_LOCAL_APIC
883 def_bool y
884 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
885
886 config X86_IO_APIC
887 def_bool y
888 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
889 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
890 select IRQ_DOMAIN
891
892 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
893 bool "Reroute for broken boot IRQs"
894 depends on X86_IO_APIC
895 ---help---
896 This option enables a workaround that fixes a source of
897 spurious interrupts. This is recommended when threaded
898 interrupt handling is used on systems where the generation of
899 superfluous "boot interrupts" cannot be disabled.
900
901 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
902 entry in the chipset's IO-APIC is masked (as, e.g. the RT
903 kernel does during interrupt handling). On chipsets where this
904 boot IRQ generation cannot be disabled, this workaround keeps
905 the original IRQ line masked so that only the equivalent "boot
906 IRQ" is delivered to the CPUs. The workaround also tells the
907 kernel to set up the IRQ handler on the boot IRQ line. In this
908 way only one interrupt is delivered to the kernel. Otherwise
909 the spurious second interrupt may cause the kernel to bring
910 down (vital) interrupt lines.
911
912 Only affects "broken" chipsets. Interrupt sharing may be
913 increased on these systems.
914
915 config X86_MCE
916 bool "Machine Check / overheating reporting"
917 default y
918 ---help---
919 Machine Check support allows the processor to notify the
920 kernel if it detects a problem (e.g. overheating, data corruption).
921 The action the kernel takes depends on the severity of the problem,
922 ranging from warning messages to halting the machine.
923
924 config X86_MCE_INTEL
925 def_bool y
926 prompt "Intel MCE features"
927 depends on X86_MCE && X86_LOCAL_APIC
928 ---help---
929 Additional support for intel specific MCE features such as
930 the thermal monitor.
931
932 config X86_MCE_AMD
933 def_bool y
934 prompt "AMD MCE features"
935 depends on X86_MCE && X86_LOCAL_APIC
936 ---help---
937 Additional support for AMD specific MCE features such as
938 the DRAM Error Threshold.
939
940 config X86_ANCIENT_MCE
941 bool "Support for old Pentium 5 / WinChip machine checks"
942 depends on X86_32 && X86_MCE
943 ---help---
944 Include support for machine check handling on old Pentium 5 or WinChip
945 systems. These typically need to be enabled explicitly on the command
946 line.
947
948 config X86_MCE_THRESHOLD
949 depends on X86_MCE_AMD || X86_MCE_INTEL
950 def_bool y
951
952 config X86_MCE_INJECT
953 depends on X86_MCE
954 tristate "Machine check injector support"
955 ---help---
956 Provide support for injecting machine checks for testing purposes.
957 If you don't know what a machine check is and you don't do kernel
958 QA it is safe to say n.
959
960 config X86_THERMAL_VECTOR
961 def_bool y
962 depends on X86_MCE_INTEL
963
964 config VM86
965 bool "Enable VM86 support" if EXPERT
966 default y
967 depends on X86_32
968 ---help---
969 This option is required by programs like DOSEMU to run
970 16-bit real mode legacy code on x86 processors. It also may
971 be needed by software like XFree86 to initialize some video
972 cards via BIOS. Disabling this option saves about 6K.
973
974 config X86_16BIT
975 bool "Enable support for 16-bit segments" if EXPERT
976 default y
977 ---help---
978 This option is required by programs like Wine to run 16-bit
979 protected mode legacy code on x86 processors. Disabling
980 this option saves about 300 bytes on i386, or around 6K text
981 plus 16K runtime memory on x86-64,
982
983 config X86_ESPFIX32
984 def_bool y
985 depends on X86_16BIT && X86_32
986
987 config X86_ESPFIX64
988 def_bool y
989 depends on X86_16BIT && X86_64
990
991 config TOSHIBA
992 tristate "Toshiba Laptop support"
993 depends on X86_32
994 ---help---
995 This adds a driver to safely access the System Management Mode of
996 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
997 not work on models with a Phoenix BIOS. The System Management Mode
998 is used to set the BIOS and power saving options on Toshiba portables.
999
1000 For information on utilities to make use of this driver see the
1001 Toshiba Linux utilities web site at:
1002 <http://www.buzzard.org.uk/toshiba/>.
1003
1004 Say Y if you intend to run this kernel on a Toshiba portable.
1005 Say N otherwise.
1006
1007 config I8K
1008 tristate "Dell laptop support"
1009 select HWMON
1010 ---help---
1011 This adds a driver to safely access the System Management Mode
1012 of the CPU on the Dell Inspiron 8000. The System Management Mode
1013 is used to read cpu temperature and cooling fan status and to
1014 control the fans on the I8K portables.
1015
1016 This driver has been tested only on the Inspiron 8000 but it may
1017 also work with other Dell laptops. You can force loading on other
1018 models by passing the parameter `force=1' to the module. Use at
1019 your own risk.
1020
1021 For information on utilities to make use of this driver see the
1022 I8K Linux utilities web site at:
1023 <http://people.debian.org/~dz/i8k/>
1024
1025 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1026 Say N otherwise.
1027
1028 config X86_REBOOTFIXUPS
1029 bool "Enable X86 board specific fixups for reboot"
1030 depends on X86_32
1031 ---help---
1032 This enables chipset and/or board specific fixups to be done
1033 in order to get reboot to work correctly. This is only needed on
1034 some combinations of hardware and BIOS. The symptom, for which
1035 this config is intended, is when reboot ends with a stalled/hung
1036 system.
1037
1038 Currently, the only fixup is for the Geode machines using
1039 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1040
1041 Say Y if you want to enable the fixup. Currently, it's safe to
1042 enable this option even if you don't need it.
1043 Say N otherwise.
1044
1045 config MICROCODE
1046 tristate "CPU microcode loading support"
1047 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1048 select FW_LOADER
1049 ---help---
1050
1051 If you say Y here, you will be able to update the microcode on
1052 certain Intel and AMD processors. The Intel support is for the
1053 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1054 Xeon etc. The AMD support is for families 0x10 and later. You will
1055 obviously need the actual microcode binary data itself which is not
1056 shipped with the Linux kernel.
1057
1058 This option selects the general module only, you need to select
1059 at least one vendor specific module as well.
1060
1061 To compile this driver as a module, choose M here: the module
1062 will be called microcode.
1063
1064 config MICROCODE_INTEL
1065 bool "Intel microcode loading support"
1066 depends on MICROCODE
1067 default MICROCODE
1068 select FW_LOADER
1069 ---help---
1070 This options enables microcode patch loading support for Intel
1071 processors.
1072
1073 For the current Intel microcode data package go to
1074 <https://downloadcenter.intel.com> and search for
1075 'Linux Processor Microcode Data File'.
1076
1077 config MICROCODE_AMD
1078 bool "AMD microcode loading support"
1079 depends on MICROCODE
1080 select FW_LOADER
1081 ---help---
1082 If you select this option, microcode patch loading support for AMD
1083 processors will be enabled.
1084
1085 config MICROCODE_OLD_INTERFACE
1086 def_bool y
1087 depends on MICROCODE
1088
1089 config MICROCODE_INTEL_EARLY
1090 def_bool n
1091
1092 config MICROCODE_AMD_EARLY
1093 def_bool n
1094
1095 config MICROCODE_EARLY
1096 bool "Early load microcode"
1097 depends on MICROCODE=y && BLK_DEV_INITRD
1098 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1099 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1100 default y
1101 help
1102 This option provides functionality to read additional microcode data
1103 at the beginning of initrd image. The data tells kernel to load
1104 microcode to CPU's as early as possible. No functional change if no
1105 microcode data is glued to the initrd, therefore it's safe to say Y.
1106
1107 config X86_MSR
1108 tristate "/dev/cpu/*/msr - Model-specific register support"
1109 ---help---
1110 This device gives privileged processes access to the x86
1111 Model-Specific Registers (MSRs). It is a character device with
1112 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1113 MSR accesses are directed to a specific CPU on multi-processor
1114 systems.
1115
1116 config X86_CPUID
1117 tristate "/dev/cpu/*/cpuid - CPU information support"
1118 ---help---
1119 This device gives processes access to the x86 CPUID instruction to
1120 be executed on a specific processor. It is a character device
1121 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1122 /dev/cpu/31/cpuid.
1123
1124 choice
1125 prompt "High Memory Support"
1126 default HIGHMEM4G
1127 depends on X86_32
1128
1129 config NOHIGHMEM
1130 bool "off"
1131 ---help---
1132 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1133 However, the address space of 32-bit x86 processors is only 4
1134 Gigabytes large. That means that, if you have a large amount of
1135 physical memory, not all of it can be "permanently mapped" by the
1136 kernel. The physical memory that's not permanently mapped is called
1137 "high memory".
1138
1139 If you are compiling a kernel which will never run on a machine with
1140 more than 1 Gigabyte total physical RAM, answer "off" here (default
1141 choice and suitable for most users). This will result in a "3GB/1GB"
1142 split: 3GB are mapped so that each process sees a 3GB virtual memory
1143 space and the remaining part of the 4GB virtual memory space is used
1144 by the kernel to permanently map as much physical memory as
1145 possible.
1146
1147 If the machine has between 1 and 4 Gigabytes physical RAM, then
1148 answer "4GB" here.
1149
1150 If more than 4 Gigabytes is used then answer "64GB" here. This
1151 selection turns Intel PAE (Physical Address Extension) mode on.
1152 PAE implements 3-level paging on IA32 processors. PAE is fully
1153 supported by Linux, PAE mode is implemented on all recent Intel
1154 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1155 then the kernel will not boot on CPUs that don't support PAE!
1156
1157 The actual amount of total physical memory will either be
1158 auto detected or can be forced by using a kernel command line option
1159 such as "mem=256M". (Try "man bootparam" or see the documentation of
1160 your boot loader (lilo or loadlin) about how to pass options to the
1161 kernel at boot time.)
1162
1163 If unsure, say "off".
1164
1165 config HIGHMEM4G
1166 bool "4GB"
1167 ---help---
1168 Select this if you have a 32-bit processor and between 1 and 4
1169 gigabytes of physical RAM.
1170
1171 config HIGHMEM64G
1172 bool "64GB"
1173 depends on !M486
1174 select X86_PAE
1175 ---help---
1176 Select this if you have a 32-bit processor and more than 4
1177 gigabytes of physical RAM.
1178
1179 endchoice
1180
1181 choice
1182 prompt "Memory split" if EXPERT
1183 default VMSPLIT_3G
1184 depends on X86_32
1185 ---help---
1186 Select the desired split between kernel and user memory.
1187
1188 If the address range available to the kernel is less than the
1189 physical memory installed, the remaining memory will be available
1190 as "high memory". Accessing high memory is a little more costly
1191 than low memory, as it needs to be mapped into the kernel first.
1192 Note that increasing the kernel address space limits the range
1193 available to user programs, making the address space there
1194 tighter. Selecting anything other than the default 3G/1G split
1195 will also likely make your kernel incompatible with binary-only
1196 kernel modules.
1197
1198 If you are not absolutely sure what you are doing, leave this
1199 option alone!
1200
1201 config VMSPLIT_3G
1202 bool "3G/1G user/kernel split"
1203 config VMSPLIT_3G_OPT
1204 depends on !X86_PAE
1205 bool "3G/1G user/kernel split (for full 1G low memory)"
1206 config VMSPLIT_2G
1207 bool "2G/2G user/kernel split"
1208 config VMSPLIT_2G_OPT
1209 depends on !X86_PAE
1210 bool "2G/2G user/kernel split (for full 2G low memory)"
1211 config VMSPLIT_1G
1212 bool "1G/3G user/kernel split"
1213 endchoice
1214
1215 config PAGE_OFFSET
1216 hex
1217 default 0xB0000000 if VMSPLIT_3G_OPT
1218 default 0x80000000 if VMSPLIT_2G
1219 default 0x78000000 if VMSPLIT_2G_OPT
1220 default 0x40000000 if VMSPLIT_1G
1221 default 0xC0000000
1222 depends on X86_32
1223
1224 config HIGHMEM
1225 def_bool y
1226 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1227
1228 config X86_PAE
1229 bool "PAE (Physical Address Extension) Support"
1230 depends on X86_32 && !HIGHMEM4G
1231 ---help---
1232 PAE is required for NX support, and furthermore enables
1233 larger swapspace support for non-overcommit purposes. It
1234 has the cost of more pagetable lookup overhead, and also
1235 consumes more pagetable space per process.
1236
1237 config ARCH_PHYS_ADDR_T_64BIT
1238 def_bool y
1239 depends on X86_64 || X86_PAE
1240
1241 config ARCH_DMA_ADDR_T_64BIT
1242 def_bool y
1243 depends on X86_64 || HIGHMEM64G
1244
1245 config DIRECT_GBPAGES
1246 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1247 default y
1248 depends on X86_64
1249 ---help---
1250 Allow the kernel linear mapping to use 1GB pages on CPUs that
1251 support it. This can improve the kernel's performance a tiny bit by
1252 reducing TLB pressure. If in doubt, say "Y".
1253
1254 # Common NUMA Features
1255 config NUMA
1256 bool "Numa Memory Allocation and Scheduler Support"
1257 depends on SMP
1258 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1259 default y if X86_BIGSMP
1260 ---help---
1261 Enable NUMA (Non Uniform Memory Access) support.
1262
1263 The kernel will try to allocate memory used by a CPU on the
1264 local memory controller of the CPU and add some more
1265 NUMA awareness to the kernel.
1266
1267 For 64-bit this is recommended if the system is Intel Core i7
1268 (or later), AMD Opteron, or EM64T NUMA.
1269
1270 For 32-bit this is only needed if you boot a 32-bit
1271 kernel on a 64-bit NUMA platform.
1272
1273 Otherwise, you should say N.
1274
1275 config AMD_NUMA
1276 def_bool y
1277 prompt "Old style AMD Opteron NUMA detection"
1278 depends on X86_64 && NUMA && PCI
1279 ---help---
1280 Enable AMD NUMA node topology detection. You should say Y here if
1281 you have a multi processor AMD system. This uses an old method to
1282 read the NUMA configuration directly from the builtin Northbridge
1283 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1284 which also takes priority if both are compiled in.
1285
1286 config X86_64_ACPI_NUMA
1287 def_bool y
1288 prompt "ACPI NUMA detection"
1289 depends on X86_64 && NUMA && ACPI && PCI
1290 select ACPI_NUMA
1291 ---help---
1292 Enable ACPI SRAT based node topology detection.
1293
1294 # Some NUMA nodes have memory ranges that span
1295 # other nodes. Even though a pfn is valid and
1296 # between a node's start and end pfns, it may not
1297 # reside on that node. See memmap_init_zone()
1298 # for details.
1299 config NODES_SPAN_OTHER_NODES
1300 def_bool y
1301 depends on X86_64_ACPI_NUMA
1302
1303 config NUMA_EMU
1304 bool "NUMA emulation"
1305 depends on NUMA
1306 ---help---
1307 Enable NUMA emulation. A flat machine will be split
1308 into virtual nodes when booted with "numa=fake=N", where N is the
1309 number of nodes. This is only useful for debugging.
1310
1311 config NODES_SHIFT
1312 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1313 range 1 10
1314 default "10" if MAXSMP
1315 default "6" if X86_64
1316 default "3"
1317 depends on NEED_MULTIPLE_NODES
1318 ---help---
1319 Specify the maximum number of NUMA Nodes available on the target
1320 system. Increases memory reserved to accommodate various tables.
1321
1322 config ARCH_HAVE_MEMORY_PRESENT
1323 def_bool y
1324 depends on X86_32 && DISCONTIGMEM
1325
1326 config NEED_NODE_MEMMAP_SIZE
1327 def_bool y
1328 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1329
1330 config ARCH_FLATMEM_ENABLE
1331 def_bool y
1332 depends on X86_32 && !NUMA
1333
1334 config ARCH_DISCONTIGMEM_ENABLE
1335 def_bool y
1336 depends on NUMA && X86_32
1337
1338 config ARCH_DISCONTIGMEM_DEFAULT
1339 def_bool y
1340 depends on NUMA && X86_32
1341
1342 config ARCH_SPARSEMEM_ENABLE
1343 def_bool y
1344 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1345 select SPARSEMEM_STATIC if X86_32
1346 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1347
1348 config ARCH_SPARSEMEM_DEFAULT
1349 def_bool y
1350 depends on X86_64
1351
1352 config ARCH_SELECT_MEMORY_MODEL
1353 def_bool y
1354 depends on ARCH_SPARSEMEM_ENABLE
1355
1356 config ARCH_MEMORY_PROBE
1357 bool "Enable sysfs memory/probe interface"
1358 depends on X86_64 && MEMORY_HOTPLUG
1359 help
1360 This option enables a sysfs memory/probe interface for testing.
1361 See Documentation/memory-hotplug.txt for more information.
1362 If you are unsure how to answer this question, answer N.
1363
1364 config ARCH_PROC_KCORE_TEXT
1365 def_bool y
1366 depends on X86_64 && PROC_KCORE
1367
1368 config ILLEGAL_POINTER_VALUE
1369 hex
1370 default 0 if X86_32
1371 default 0xdead000000000000 if X86_64
1372
1373 source "mm/Kconfig"
1374
1375 config HIGHPTE
1376 bool "Allocate 3rd-level pagetables from highmem"
1377 depends on HIGHMEM
1378 ---help---
1379 The VM uses one page table entry for each page of physical memory.
1380 For systems with a lot of RAM, this can be wasteful of precious
1381 low memory. Setting this option will put user-space page table
1382 entries in high memory.
1383
1384 config X86_CHECK_BIOS_CORRUPTION
1385 bool "Check for low memory corruption"
1386 ---help---
1387 Periodically check for memory corruption in low memory, which
1388 is suspected to be caused by BIOS. Even when enabled in the
1389 configuration, it is disabled at runtime. Enable it by
1390 setting "memory_corruption_check=1" on the kernel command
1391 line. By default it scans the low 64k of memory every 60
1392 seconds; see the memory_corruption_check_size and
1393 memory_corruption_check_period parameters in
1394 Documentation/kernel-parameters.txt to adjust this.
1395
1396 When enabled with the default parameters, this option has
1397 almost no overhead, as it reserves a relatively small amount
1398 of memory and scans it infrequently. It both detects corruption
1399 and prevents it from affecting the running system.
1400
1401 It is, however, intended as a diagnostic tool; if repeatable
1402 BIOS-originated corruption always affects the same memory,
1403 you can use memmap= to prevent the kernel from using that
1404 memory.
1405
1406 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1407 bool "Set the default setting of memory_corruption_check"
1408 depends on X86_CHECK_BIOS_CORRUPTION
1409 default y
1410 ---help---
1411 Set whether the default state of memory_corruption_check is
1412 on or off.
1413
1414 config X86_RESERVE_LOW
1415 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1416 default 64
1417 range 4 640
1418 ---help---
1419 Specify the amount of low memory to reserve for the BIOS.
1420
1421 The first page contains BIOS data structures that the kernel
1422 must not use, so that page must always be reserved.
1423
1424 By default we reserve the first 64K of physical RAM, as a
1425 number of BIOSes are known to corrupt that memory range
1426 during events such as suspend/resume or monitor cable
1427 insertion, so it must not be used by the kernel.
1428
1429 You can set this to 4 if you are absolutely sure that you
1430 trust the BIOS to get all its memory reservations and usages
1431 right. If you know your BIOS have problems beyond the
1432 default 64K area, you can set this to 640 to avoid using the
1433 entire low memory range.
1434
1435 If you have doubts about the BIOS (e.g. suspend/resume does
1436 not work or there's kernel crashes after certain hardware
1437 hotplug events) then you might want to enable
1438 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1439 typical corruption patterns.
1440
1441 Leave this to the default value of 64 if you are unsure.
1442
1443 config MATH_EMULATION
1444 bool
1445 prompt "Math emulation" if X86_32
1446 ---help---
1447 Linux can emulate a math coprocessor (used for floating point
1448 operations) if you don't have one. 486DX and Pentium processors have
1449 a math coprocessor built in, 486SX and 386 do not, unless you added
1450 a 487DX or 387, respectively. (The messages during boot time can
1451 give you some hints here ["man dmesg"].) Everyone needs either a
1452 coprocessor or this emulation.
1453
1454 If you don't have a math coprocessor, you need to say Y here; if you
1455 say Y here even though you have a coprocessor, the coprocessor will
1456 be used nevertheless. (This behavior can be changed with the kernel
1457 command line option "no387", which comes handy if your coprocessor
1458 is broken. Try "man bootparam" or see the documentation of your boot
1459 loader (lilo or loadlin) about how to pass options to the kernel at
1460 boot time.) This means that it is a good idea to say Y here if you
1461 intend to use this kernel on different machines.
1462
1463 More information about the internals of the Linux math coprocessor
1464 emulation can be found in <file:arch/x86/math-emu/README>.
1465
1466 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1467 kernel, it won't hurt.
1468
1469 config MTRR
1470 def_bool y
1471 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1472 ---help---
1473 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1474 the Memory Type Range Registers (MTRRs) may be used to control
1475 processor access to memory ranges. This is most useful if you have
1476 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1477 allows bus write transfers to be combined into a larger transfer
1478 before bursting over the PCI/AGP bus. This can increase performance
1479 of image write operations 2.5 times or more. Saying Y here creates a
1480 /proc/mtrr file which may be used to manipulate your processor's
1481 MTRRs. Typically the X server should use this.
1482
1483 This code has a reasonably generic interface so that similar
1484 control registers on other processors can be easily supported
1485 as well:
1486
1487 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1488 Registers (ARRs) which provide a similar functionality to MTRRs. For
1489 these, the ARRs are used to emulate the MTRRs.
1490 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1491 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1492 write-combining. All of these processors are supported by this code
1493 and it makes sense to say Y here if you have one of them.
1494
1495 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1496 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1497 can lead to all sorts of problems, so it's good to say Y here.
1498
1499 You can safely say Y even if your machine doesn't have MTRRs, you'll
1500 just add about 9 KB to your kernel.
1501
1502 See <file:Documentation/x86/mtrr.txt> for more information.
1503
1504 config MTRR_SANITIZER
1505 def_bool y
1506 prompt "MTRR cleanup support"
1507 depends on MTRR
1508 ---help---
1509 Convert MTRR layout from continuous to discrete, so X drivers can
1510 add writeback entries.
1511
1512 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1513 The largest mtrr entry size for a continuous block can be set with
1514 mtrr_chunk_size.
1515
1516 If unsure, say Y.
1517
1518 config MTRR_SANITIZER_ENABLE_DEFAULT
1519 int "MTRR cleanup enable value (0-1)"
1520 range 0 1
1521 default "0"
1522 depends on MTRR_SANITIZER
1523 ---help---
1524 Enable mtrr cleanup default value
1525
1526 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1527 int "MTRR cleanup spare reg num (0-7)"
1528 range 0 7
1529 default "1"
1530 depends on MTRR_SANITIZER
1531 ---help---
1532 mtrr cleanup spare entries default, it can be changed via
1533 mtrr_spare_reg_nr=N on the kernel command line.
1534
1535 config X86_PAT
1536 def_bool y
1537 prompt "x86 PAT support" if EXPERT
1538 depends on MTRR
1539 ---help---
1540 Use PAT attributes to setup page level cache control.
1541
1542 PATs are the modern equivalents of MTRRs and are much more
1543 flexible than MTRRs.
1544
1545 Say N here if you see bootup problems (boot crash, boot hang,
1546 spontaneous reboots) or a non-working video driver.
1547
1548 If unsure, say Y.
1549
1550 config ARCH_USES_PG_UNCACHED
1551 def_bool y
1552 depends on X86_PAT
1553
1554 config ARCH_RANDOM
1555 def_bool y
1556 prompt "x86 architectural random number generator" if EXPERT
1557 ---help---
1558 Enable the x86 architectural RDRAND instruction
1559 (Intel Bull Mountain technology) to generate random numbers.
1560 If supported, this is a high bandwidth, cryptographically
1561 secure hardware random number generator.
1562
1563 config X86_SMAP
1564 def_bool y
1565 prompt "Supervisor Mode Access Prevention" if EXPERT
1566 ---help---
1567 Supervisor Mode Access Prevention (SMAP) is a security
1568 feature in newer Intel processors. There is a small
1569 performance cost if this enabled and turned on; there is
1570 also a small increase in the kernel size if this is enabled.
1571
1572 If unsure, say Y.
1573
1574 config EFI
1575 bool "EFI runtime service support"
1576 depends on ACPI
1577 select UCS2_STRING
1578 select EFI_RUNTIME_WRAPPERS
1579 ---help---
1580 This enables the kernel to use EFI runtime services that are
1581 available (such as the EFI variable services).
1582
1583 This option is only useful on systems that have EFI firmware.
1584 In addition, you should use the latest ELILO loader available
1585 at <http://elilo.sourceforge.net> in order to take advantage
1586 of EFI runtime services. However, even with this option, the
1587 resultant kernel should continue to boot on existing non-EFI
1588 platforms.
1589
1590 config EFI_STUB
1591 bool "EFI stub support"
1592 depends on EFI && !X86_USE_3DNOW
1593 select RELOCATABLE
1594 ---help---
1595 This kernel feature allows a bzImage to be loaded directly
1596 by EFI firmware without the use of a bootloader.
1597
1598 See Documentation/efi-stub.txt for more information.
1599
1600 config EFI_MIXED
1601 bool "EFI mixed-mode support"
1602 depends on EFI_STUB && X86_64
1603 ---help---
1604 Enabling this feature allows a 64-bit kernel to be booted
1605 on a 32-bit firmware, provided that your CPU supports 64-bit
1606 mode.
1607
1608 Note that it is not possible to boot a mixed-mode enabled
1609 kernel via the EFI boot stub - a bootloader that supports
1610 the EFI handover protocol must be used.
1611
1612 If unsure, say N.
1613
1614 config SECCOMP
1615 def_bool y
1616 prompt "Enable seccomp to safely compute untrusted bytecode"
1617 ---help---
1618 This kernel feature is useful for number crunching applications
1619 that may need to compute untrusted bytecode during their
1620 execution. By using pipes or other transports made available to
1621 the process as file descriptors supporting the read/write
1622 syscalls, it's possible to isolate those applications in
1623 their own address space using seccomp. Once seccomp is
1624 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1625 and the task is only allowed to execute a few safe syscalls
1626 defined by each seccomp mode.
1627
1628 If unsure, say Y. Only embedded should say N here.
1629
1630 source kernel/Kconfig.hz
1631
1632 config KEXEC
1633 bool "kexec system call"
1634 ---help---
1635 kexec is a system call that implements the ability to shutdown your
1636 current kernel, and to start another kernel. It is like a reboot
1637 but it is independent of the system firmware. And like a reboot
1638 you can start any kernel with it, not just Linux.
1639
1640 The name comes from the similarity to the exec system call.
1641
1642 It is an ongoing process to be certain the hardware in a machine
1643 is properly shutdown, so do not be surprised if this code does not
1644 initially work for you. As of this writing the exact hardware
1645 interface is strongly in flux, so no good recommendation can be
1646 made.
1647
1648 config KEXEC_FILE
1649 bool "kexec file based system call"
1650 select BUILD_BIN2C
1651 depends on KEXEC
1652 depends on X86_64
1653 depends on CRYPTO=y
1654 depends on CRYPTO_SHA256=y
1655 ---help---
1656 This is new version of kexec system call. This system call is
1657 file based and takes file descriptors as system call argument
1658 for kernel and initramfs as opposed to list of segments as
1659 accepted by previous system call.
1660
1661 config KEXEC_VERIFY_SIG
1662 bool "Verify kernel signature during kexec_file_load() syscall"
1663 depends on KEXEC_FILE
1664 ---help---
1665 This option makes kernel signature verification mandatory for
1666 kexec_file_load() syscall. If kernel is signature can not be
1667 verified, kexec_file_load() will fail.
1668
1669 This option enforces signature verification at generic level.
1670 One needs to enable signature verification for type of kernel
1671 image being loaded to make sure it works. For example, enable
1672 bzImage signature verification option to be able to load and
1673 verify signatures of bzImage. Otherwise kernel loading will fail.
1674
1675 config KEXEC_BZIMAGE_VERIFY_SIG
1676 bool "Enable bzImage signature verification support"
1677 depends on KEXEC_VERIFY_SIG
1678 depends on SIGNED_PE_FILE_VERIFICATION
1679 select SYSTEM_TRUSTED_KEYRING
1680 ---help---
1681 Enable bzImage signature verification support.
1682
1683 config CRASH_DUMP
1684 bool "kernel crash dumps"
1685 depends on X86_64 || (X86_32 && HIGHMEM)
1686 ---help---
1687 Generate crash dump after being started by kexec.
1688 This should be normally only set in special crash dump kernels
1689 which are loaded in the main kernel with kexec-tools into
1690 a specially reserved region and then later executed after
1691 a crash by kdump/kexec. The crash dump kernel must be compiled
1692 to a memory address not used by the main kernel or BIOS using
1693 PHYSICAL_START, or it must be built as a relocatable image
1694 (CONFIG_RELOCATABLE=y).
1695 For more details see Documentation/kdump/kdump.txt
1696
1697 config KEXEC_JUMP
1698 bool "kexec jump"
1699 depends on KEXEC && HIBERNATION
1700 ---help---
1701 Jump between original kernel and kexeced kernel and invoke
1702 code in physical address mode via KEXEC
1703
1704 config PHYSICAL_START
1705 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1706 default "0x1000000"
1707 ---help---
1708 This gives the physical address where the kernel is loaded.
1709
1710 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1711 bzImage will decompress itself to above physical address and
1712 run from there. Otherwise, bzImage will run from the address where
1713 it has been loaded by the boot loader and will ignore above physical
1714 address.
1715
1716 In normal kdump cases one does not have to set/change this option
1717 as now bzImage can be compiled as a completely relocatable image
1718 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1719 address. This option is mainly useful for the folks who don't want
1720 to use a bzImage for capturing the crash dump and want to use a
1721 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1722 to be specifically compiled to run from a specific memory area
1723 (normally a reserved region) and this option comes handy.
1724
1725 So if you are using bzImage for capturing the crash dump,
1726 leave the value here unchanged to 0x1000000 and set
1727 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1728 for capturing the crash dump change this value to start of
1729 the reserved region. In other words, it can be set based on
1730 the "X" value as specified in the "crashkernel=YM@XM"
1731 command line boot parameter passed to the panic-ed
1732 kernel. Please take a look at Documentation/kdump/kdump.txt
1733 for more details about crash dumps.
1734
1735 Usage of bzImage for capturing the crash dump is recommended as
1736 one does not have to build two kernels. Same kernel can be used
1737 as production kernel and capture kernel. Above option should have
1738 gone away after relocatable bzImage support is introduced. But it
1739 is present because there are users out there who continue to use
1740 vmlinux for dump capture. This option should go away down the
1741 line.
1742
1743 Don't change this unless you know what you are doing.
1744
1745 config RELOCATABLE
1746 bool "Build a relocatable kernel"
1747 default y
1748 ---help---
1749 This builds a kernel image that retains relocation information
1750 so it can be loaded someplace besides the default 1MB.
1751 The relocations tend to make the kernel binary about 10% larger,
1752 but are discarded at runtime.
1753
1754 One use is for the kexec on panic case where the recovery kernel
1755 must live at a different physical address than the primary
1756 kernel.
1757
1758 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1759 it has been loaded at and the compile time physical address
1760 (CONFIG_PHYSICAL_START) is used as the minimum location.
1761
1762 config RANDOMIZE_BASE
1763 bool "Randomize the address of the kernel image"
1764 depends on RELOCATABLE
1765 default n
1766 ---help---
1767 Randomizes the physical and virtual address at which the
1768 kernel image is decompressed, as a security feature that
1769 deters exploit attempts relying on knowledge of the location
1770 of kernel internals.
1771
1772 Entropy is generated using the RDRAND instruction if it is
1773 supported. If RDTSC is supported, it is used as well. If
1774 neither RDRAND nor RDTSC are supported, then randomness is
1775 read from the i8254 timer.
1776
1777 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1778 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1779 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1780 minimum of 2MiB, only 10 bits of entropy is theoretically
1781 possible. At best, due to page table layouts, 64-bit can use
1782 9 bits of entropy and 32-bit uses 8 bits.
1783
1784 If unsure, say N.
1785
1786 config RANDOMIZE_BASE_MAX_OFFSET
1787 hex "Maximum kASLR offset allowed" if EXPERT
1788 depends on RANDOMIZE_BASE
1789 range 0x0 0x20000000 if X86_32
1790 default "0x20000000" if X86_32
1791 range 0x0 0x40000000 if X86_64
1792 default "0x40000000" if X86_64
1793 ---help---
1794 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1795 memory is used to determine the maximal offset in bytes that will
1796 be applied to the kernel when kernel Address Space Layout
1797 Randomization (kASLR) is active. This must be a multiple of
1798 PHYSICAL_ALIGN.
1799
1800 On 32-bit this is limited to 512MiB by page table layouts. The
1801 default is 512MiB.
1802
1803 On 64-bit this is limited by how the kernel fixmap page table is
1804 positioned, so this cannot be larger than 1GiB currently. Without
1805 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1806 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1807 modules area will shrink to compensate, up to the current maximum
1808 1GiB to 1GiB split. The default is 1GiB.
1809
1810 If unsure, leave at the default value.
1811
1812 # Relocation on x86 needs some additional build support
1813 config X86_NEED_RELOCS
1814 def_bool y
1815 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1816
1817 config PHYSICAL_ALIGN
1818 hex "Alignment value to which kernel should be aligned"
1819 default "0x200000"
1820 range 0x2000 0x1000000 if X86_32
1821 range 0x200000 0x1000000 if X86_64
1822 ---help---
1823 This value puts the alignment restrictions on physical address
1824 where kernel is loaded and run from. Kernel is compiled for an
1825 address which meets above alignment restriction.
1826
1827 If bootloader loads the kernel at a non-aligned address and
1828 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1829 address aligned to above value and run from there.
1830
1831 If bootloader loads the kernel at a non-aligned address and
1832 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1833 load address and decompress itself to the address it has been
1834 compiled for and run from there. The address for which kernel is
1835 compiled already meets above alignment restrictions. Hence the
1836 end result is that kernel runs from a physical address meeting
1837 above alignment restrictions.
1838
1839 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1840 this value must be a multiple of 0x200000.
1841
1842 Don't change this unless you know what you are doing.
1843
1844 config HOTPLUG_CPU
1845 bool "Support for hot-pluggable CPUs"
1846 depends on SMP
1847 ---help---
1848 Say Y here to allow turning CPUs off and on. CPUs can be
1849 controlled through /sys/devices/system/cpu.
1850 ( Note: power management support will enable this option
1851 automatically on SMP systems. )
1852 Say N if you want to disable CPU hotplug.
1853
1854 config BOOTPARAM_HOTPLUG_CPU0
1855 bool "Set default setting of cpu0_hotpluggable"
1856 default n
1857 depends on HOTPLUG_CPU
1858 ---help---
1859 Set whether default state of cpu0_hotpluggable is on or off.
1860
1861 Say Y here to enable CPU0 hotplug by default. If this switch
1862 is turned on, there is no need to give cpu0_hotplug kernel
1863 parameter and the CPU0 hotplug feature is enabled by default.
1864
1865 Please note: there are two known CPU0 dependencies if you want
1866 to enable the CPU0 hotplug feature either by this switch or by
1867 cpu0_hotplug kernel parameter.
1868
1869 First, resume from hibernate or suspend always starts from CPU0.
1870 So hibernate and suspend are prevented if CPU0 is offline.
1871
1872 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1873 offline if any interrupt can not migrate out of CPU0. There may
1874 be other CPU0 dependencies.
1875
1876 Please make sure the dependencies are under your control before
1877 you enable this feature.
1878
1879 Say N if you don't want to enable CPU0 hotplug feature by default.
1880 You still can enable the CPU0 hotplug feature at boot by kernel
1881 parameter cpu0_hotplug.
1882
1883 config DEBUG_HOTPLUG_CPU0
1884 def_bool n
1885 prompt "Debug CPU0 hotplug"
1886 depends on HOTPLUG_CPU
1887 ---help---
1888 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1889 soon as possible and boots up userspace with CPU0 offlined. User
1890 can online CPU0 back after boot time.
1891
1892 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1893 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1894 compilation or giving cpu0_hotplug kernel parameter at boot.
1895
1896 If unsure, say N.
1897
1898 config COMPAT_VDSO
1899 def_bool n
1900 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1901 depends on X86_32 || IA32_EMULATION
1902 ---help---
1903 Certain buggy versions of glibc will crash if they are
1904 presented with a 32-bit vDSO that is not mapped at the address
1905 indicated in its segment table.
1906
1907 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1908 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1909 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1910 the only released version with the bug, but OpenSUSE 9
1911 contains a buggy "glibc 2.3.2".
1912
1913 The symptom of the bug is that everything crashes on startup, saying:
1914 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1915
1916 Saying Y here changes the default value of the vdso32 boot
1917 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1918 This works around the glibc bug but hurts performance.
1919
1920 If unsure, say N: if you are compiling your own kernel, you
1921 are unlikely to be using a buggy version of glibc.
1922
1923 config CMDLINE_BOOL
1924 bool "Built-in kernel command line"
1925 ---help---
1926 Allow for specifying boot arguments to the kernel at
1927 build time. On some systems (e.g. embedded ones), it is
1928 necessary or convenient to provide some or all of the
1929 kernel boot arguments with the kernel itself (that is,
1930 to not rely on the boot loader to provide them.)
1931
1932 To compile command line arguments into the kernel,
1933 set this option to 'Y', then fill in the
1934 the boot arguments in CONFIG_CMDLINE.
1935
1936 Systems with fully functional boot loaders (i.e. non-embedded)
1937 should leave this option set to 'N'.
1938
1939 config CMDLINE
1940 string "Built-in kernel command string"
1941 depends on CMDLINE_BOOL
1942 default ""
1943 ---help---
1944 Enter arguments here that should be compiled into the kernel
1945 image and used at boot time. If the boot loader provides a
1946 command line at boot time, it is appended to this string to
1947 form the full kernel command line, when the system boots.
1948
1949 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1950 change this behavior.
1951
1952 In most cases, the command line (whether built-in or provided
1953 by the boot loader) should specify the device for the root
1954 file system.
1955
1956 config CMDLINE_OVERRIDE
1957 bool "Built-in command line overrides boot loader arguments"
1958 depends on CMDLINE_BOOL
1959 ---help---
1960 Set this option to 'Y' to have the kernel ignore the boot loader
1961 command line, and use ONLY the built-in command line.
1962
1963 This is used to work around broken boot loaders. This should
1964 be set to 'N' under normal conditions.
1965
1966 endmenu
1967
1968 config ARCH_ENABLE_MEMORY_HOTPLUG
1969 def_bool y
1970 depends on X86_64 || (X86_32 && HIGHMEM)
1971
1972 config ARCH_ENABLE_MEMORY_HOTREMOVE
1973 def_bool y
1974 depends on MEMORY_HOTPLUG
1975
1976 config USE_PERCPU_NUMA_NODE_ID
1977 def_bool y
1978 depends on NUMA
1979
1980 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1981 def_bool y
1982 depends on X86_64 || X86_PAE
1983
1984 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1985 def_bool y
1986 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1987
1988 menu "Power management and ACPI options"
1989
1990 config ARCH_HIBERNATION_HEADER
1991 def_bool y
1992 depends on X86_64 && HIBERNATION
1993
1994 source "kernel/power/Kconfig"
1995
1996 source "drivers/acpi/Kconfig"
1997
1998 source "drivers/sfi/Kconfig"
1999
2000 config X86_APM_BOOT
2001 def_bool y
2002 depends on APM
2003
2004 menuconfig APM
2005 tristate "APM (Advanced Power Management) BIOS support"
2006 depends on X86_32 && PM_SLEEP
2007 ---help---
2008 APM is a BIOS specification for saving power using several different
2009 techniques. This is mostly useful for battery powered laptops with
2010 APM compliant BIOSes. If you say Y here, the system time will be
2011 reset after a RESUME operation, the /proc/apm device will provide
2012 battery status information, and user-space programs will receive
2013 notification of APM "events" (e.g. battery status change).
2014
2015 If you select "Y" here, you can disable actual use of the APM
2016 BIOS by passing the "apm=off" option to the kernel at boot time.
2017
2018 Note that the APM support is almost completely disabled for
2019 machines with more than one CPU.
2020
2021 In order to use APM, you will need supporting software. For location
2022 and more information, read <file:Documentation/power/apm-acpi.txt>
2023 and the Battery Powered Linux mini-HOWTO, available from
2024 <http://www.tldp.org/docs.html#howto>.
2025
2026 This driver does not spin down disk drives (see the hdparm(8)
2027 manpage ("man 8 hdparm") for that), and it doesn't turn off
2028 VESA-compliant "green" monitors.
2029
2030 This driver does not support the TI 4000M TravelMate and the ACER
2031 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2032 desktop machines also don't have compliant BIOSes, and this driver
2033 may cause those machines to panic during the boot phase.
2034
2035 Generally, if you don't have a battery in your machine, there isn't
2036 much point in using this driver and you should say N. If you get
2037 random kernel OOPSes or reboots that don't seem to be related to
2038 anything, try disabling/enabling this option (or disabling/enabling
2039 APM in your BIOS).
2040
2041 Some other things you should try when experiencing seemingly random,
2042 "weird" problems:
2043
2044 1) make sure that you have enough swap space and that it is
2045 enabled.
2046 2) pass the "no-hlt" option to the kernel
2047 3) switch on floating point emulation in the kernel and pass
2048 the "no387" option to the kernel
2049 4) pass the "floppy=nodma" option to the kernel
2050 5) pass the "mem=4M" option to the kernel (thereby disabling
2051 all but the first 4 MB of RAM)
2052 6) make sure that the CPU is not over clocked.
2053 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2054 8) disable the cache from your BIOS settings
2055 9) install a fan for the video card or exchange video RAM
2056 10) install a better fan for the CPU
2057 11) exchange RAM chips
2058 12) exchange the motherboard.
2059
2060 To compile this driver as a module, choose M here: the
2061 module will be called apm.
2062
2063 if APM
2064
2065 config APM_IGNORE_USER_SUSPEND
2066 bool "Ignore USER SUSPEND"
2067 ---help---
2068 This option will ignore USER SUSPEND requests. On machines with a
2069 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2070 series notebooks, it is necessary to say Y because of a BIOS bug.
2071
2072 config APM_DO_ENABLE
2073 bool "Enable PM at boot time"
2074 ---help---
2075 Enable APM features at boot time. From page 36 of the APM BIOS
2076 specification: "When disabled, the APM BIOS does not automatically
2077 power manage devices, enter the Standby State, enter the Suspend
2078 State, or take power saving steps in response to CPU Idle calls."
2079 This driver will make CPU Idle calls when Linux is idle (unless this
2080 feature is turned off -- see "Do CPU IDLE calls", below). This
2081 should always save battery power, but more complicated APM features
2082 will be dependent on your BIOS implementation. You may need to turn
2083 this option off if your computer hangs at boot time when using APM
2084 support, or if it beeps continuously instead of suspending. Turn
2085 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2086 T400CDT. This is off by default since most machines do fine without
2087 this feature.
2088
2089 config APM_CPU_IDLE
2090 depends on CPU_IDLE
2091 bool "Make CPU Idle calls when idle"
2092 ---help---
2093 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2094 On some machines, this can activate improved power savings, such as
2095 a slowed CPU clock rate, when the machine is idle. These idle calls
2096 are made after the idle loop has run for some length of time (e.g.,
2097 333 mS). On some machines, this will cause a hang at boot time or
2098 whenever the CPU becomes idle. (On machines with more than one CPU,
2099 this option does nothing.)
2100
2101 config APM_DISPLAY_BLANK
2102 bool "Enable console blanking using APM"
2103 ---help---
2104 Enable console blanking using the APM. Some laptops can use this to
2105 turn off the LCD backlight when the screen blanker of the Linux
2106 virtual console blanks the screen. Note that this is only used by
2107 the virtual console screen blanker, and won't turn off the backlight
2108 when using the X Window system. This also doesn't have anything to
2109 do with your VESA-compliant power-saving monitor. Further, this
2110 option doesn't work for all laptops -- it might not turn off your
2111 backlight at all, or it might print a lot of errors to the console,
2112 especially if you are using gpm.
2113
2114 config APM_ALLOW_INTS
2115 bool "Allow interrupts during APM BIOS calls"
2116 ---help---
2117 Normally we disable external interrupts while we are making calls to
2118 the APM BIOS as a measure to lessen the effects of a badly behaving
2119 BIOS implementation. The BIOS should reenable interrupts if it
2120 needs to. Unfortunately, some BIOSes do not -- especially those in
2121 many of the newer IBM Thinkpads. If you experience hangs when you
2122 suspend, try setting this to Y. Otherwise, say N.
2123
2124 endif # APM
2125
2126 source "drivers/cpufreq/Kconfig"
2127
2128 source "drivers/cpuidle/Kconfig"
2129
2130 source "drivers/idle/Kconfig"
2131
2132 endmenu
2133
2134
2135 menu "Bus options (PCI etc.)"
2136
2137 config PCI
2138 bool "PCI support"
2139 default y
2140 ---help---
2141 Find out whether you have a PCI motherboard. PCI is the name of a
2142 bus system, i.e. the way the CPU talks to the other stuff inside
2143 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2144 VESA. If you have PCI, say Y, otherwise N.
2145
2146 choice
2147 prompt "PCI access mode"
2148 depends on X86_32 && PCI
2149 default PCI_GOANY
2150 ---help---
2151 On PCI systems, the BIOS can be used to detect the PCI devices and
2152 determine their configuration. However, some old PCI motherboards
2153 have BIOS bugs and may crash if this is done. Also, some embedded
2154 PCI-based systems don't have any BIOS at all. Linux can also try to
2155 detect the PCI hardware directly without using the BIOS.
2156
2157 With this option, you can specify how Linux should detect the
2158 PCI devices. If you choose "BIOS", the BIOS will be used,
2159 if you choose "Direct", the BIOS won't be used, and if you
2160 choose "MMConfig", then PCI Express MMCONFIG will be used.
2161 If you choose "Any", the kernel will try MMCONFIG, then the
2162 direct access method and falls back to the BIOS if that doesn't
2163 work. If unsure, go with the default, which is "Any".
2164
2165 config PCI_GOBIOS
2166 bool "BIOS"
2167
2168 config PCI_GOMMCONFIG
2169 bool "MMConfig"
2170
2171 config PCI_GODIRECT
2172 bool "Direct"
2173
2174 config PCI_GOOLPC
2175 bool "OLPC XO-1"
2176 depends on OLPC
2177
2178 config PCI_GOANY
2179 bool "Any"
2180
2181 endchoice
2182
2183 config PCI_BIOS
2184 def_bool y
2185 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2186
2187 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2188 config PCI_DIRECT
2189 def_bool y
2190 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2191
2192 config PCI_MMCONFIG
2193 def_bool y
2194 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2195
2196 config PCI_OLPC
2197 def_bool y
2198 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2199
2200 config PCI_XEN
2201 def_bool y
2202 depends on PCI && XEN
2203 select SWIOTLB_XEN
2204
2205 config PCI_DOMAINS
2206 def_bool y
2207 depends on PCI
2208
2209 config PCI_MMCONFIG
2210 bool "Support mmconfig PCI config space access"
2211 depends on X86_64 && PCI && ACPI
2212
2213 config PCI_CNB20LE_QUIRK
2214 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2215 depends on PCI
2216 help
2217 Read the PCI windows out of the CNB20LE host bridge. This allows
2218 PCI hotplug to work on systems with the CNB20LE chipset which do
2219 not have ACPI.
2220
2221 There's no public spec for this chipset, and this functionality
2222 is known to be incomplete.
2223
2224 You should say N unless you know you need this.
2225
2226 source "drivers/pci/pcie/Kconfig"
2227
2228 source "drivers/pci/Kconfig"
2229
2230 # x86_64 have no ISA slots, but can have ISA-style DMA.
2231 config ISA_DMA_API
2232 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2233 default y
2234 help
2235 Enables ISA-style DMA support for devices requiring such controllers.
2236 If unsure, say Y.
2237
2238 if X86_32
2239
2240 config ISA
2241 bool "ISA support"
2242 ---help---
2243 Find out whether you have ISA slots on your motherboard. ISA is the
2244 name of a bus system, i.e. the way the CPU talks to the other stuff
2245 inside your box. Other bus systems are PCI, EISA, MicroChannel
2246 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2247 newer boards don't support it. If you have ISA, say Y, otherwise N.
2248
2249 config EISA
2250 bool "EISA support"
2251 depends on ISA
2252 ---help---
2253 The Extended Industry Standard Architecture (EISA) bus was
2254 developed as an open alternative to the IBM MicroChannel bus.
2255
2256 The EISA bus provided some of the features of the IBM MicroChannel
2257 bus while maintaining backward compatibility with cards made for
2258 the older ISA bus. The EISA bus saw limited use between 1988 and
2259 1995 when it was made obsolete by the PCI bus.
2260
2261 Say Y here if you are building a kernel for an EISA-based machine.
2262
2263 Otherwise, say N.
2264
2265 source "drivers/eisa/Kconfig"
2266
2267 config SCx200
2268 tristate "NatSemi SCx200 support"
2269 ---help---
2270 This provides basic support for National Semiconductor's
2271 (now AMD's) Geode processors. The driver probes for the
2272 PCI-IDs of several on-chip devices, so its a good dependency
2273 for other scx200_* drivers.
2274
2275 If compiled as a module, the driver is named scx200.
2276
2277 config SCx200HR_TIMER
2278 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2279 depends on SCx200
2280 default y
2281 ---help---
2282 This driver provides a clocksource built upon the on-chip
2283 27MHz high-resolution timer. Its also a workaround for
2284 NSC Geode SC-1100's buggy TSC, which loses time when the
2285 processor goes idle (as is done by the scheduler). The
2286 other workaround is idle=poll boot option.
2287
2288 config OLPC
2289 bool "One Laptop Per Child support"
2290 depends on !X86_PAE
2291 select GPIOLIB
2292 select OF
2293 select OF_PROMTREE
2294 select IRQ_DOMAIN
2295 ---help---
2296 Add support for detecting the unique features of the OLPC
2297 XO hardware.
2298
2299 config OLPC_XO1_PM
2300 bool "OLPC XO-1 Power Management"
2301 depends on OLPC && MFD_CS5535 && PM_SLEEP
2302 select MFD_CORE
2303 ---help---
2304 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2305
2306 config OLPC_XO1_RTC
2307 bool "OLPC XO-1 Real Time Clock"
2308 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2309 ---help---
2310 Add support for the XO-1 real time clock, which can be used as a
2311 programmable wakeup source.
2312
2313 config OLPC_XO1_SCI
2314 bool "OLPC XO-1 SCI extras"
2315 depends on OLPC && OLPC_XO1_PM
2316 depends on INPUT=y
2317 select POWER_SUPPLY
2318 select GPIO_CS5535
2319 select MFD_CORE
2320 ---help---
2321 Add support for SCI-based features of the OLPC XO-1 laptop:
2322 - EC-driven system wakeups
2323 - Power button
2324 - Ebook switch
2325 - Lid switch
2326 - AC adapter status updates
2327 - Battery status updates
2328
2329 config OLPC_XO15_SCI
2330 bool "OLPC XO-1.5 SCI extras"
2331 depends on OLPC && ACPI
2332 select POWER_SUPPLY
2333 ---help---
2334 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2335 - EC-driven system wakeups
2336 - AC adapter status updates
2337 - Battery status updates
2338
2339 config ALIX
2340 bool "PCEngines ALIX System Support (LED setup)"
2341 select GPIOLIB
2342 ---help---
2343 This option enables system support for the PCEngines ALIX.
2344 At present this just sets up LEDs for GPIO control on
2345 ALIX2/3/6 boards. However, other system specific setup should
2346 get added here.
2347
2348 Note: You must still enable the drivers for GPIO and LED support
2349 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2350
2351 Note: You have to set alix.force=1 for boards with Award BIOS.
2352
2353 config NET5501
2354 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2355 select GPIOLIB
2356 ---help---
2357 This option enables system support for the Soekris Engineering net5501.
2358
2359 config GEOS
2360 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2361 select GPIOLIB
2362 depends on DMI
2363 ---help---
2364 This option enables system support for the Traverse Technologies GEOS.
2365
2366 config TS5500
2367 bool "Technologic Systems TS-5500 platform support"
2368 depends on MELAN
2369 select CHECK_SIGNATURE
2370 select NEW_LEDS
2371 select LEDS_CLASS
2372 ---help---
2373 This option enables system support for the Technologic Systems TS-5500.
2374
2375 endif # X86_32
2376
2377 config AMD_NB
2378 def_bool y
2379 depends on CPU_SUP_AMD && PCI
2380
2381 source "drivers/pcmcia/Kconfig"
2382
2383 source "drivers/pci/hotplug/Kconfig"
2384
2385 config RAPIDIO
2386 tristate "RapidIO support"
2387 depends on PCI
2388 default n
2389 help
2390 If enabled this option will include drivers and the core
2391 infrastructure code to support RapidIO interconnect devices.
2392
2393 source "drivers/rapidio/Kconfig"
2394
2395 config X86_SYSFB
2396 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2397 help
2398 Firmwares often provide initial graphics framebuffers so the BIOS,
2399 bootloader or kernel can show basic video-output during boot for
2400 user-guidance and debugging. Historically, x86 used the VESA BIOS
2401 Extensions and EFI-framebuffers for this, which are mostly limited
2402 to x86.
2403 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2404 framebuffers so the new generic system-framebuffer drivers can be
2405 used on x86. If the framebuffer is not compatible with the generic
2406 modes, it is adverticed as fallback platform framebuffer so legacy
2407 drivers like efifb, vesafb and uvesafb can pick it up.
2408 If this option is not selected, all system framebuffers are always
2409 marked as fallback platform framebuffers as usual.
2410
2411 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2412 not be able to pick up generic system framebuffers if this option
2413 is selected. You are highly encouraged to enable simplefb as
2414 replacement if you select this option. simplefb can correctly deal
2415 with generic system framebuffers. But you should still keep vesafb
2416 and others enabled as fallback if a system framebuffer is
2417 incompatible with simplefb.
2418
2419 If unsure, say Y.
2420
2421 endmenu
2422
2423
2424 menu "Executable file formats / Emulations"
2425
2426 source "fs/Kconfig.binfmt"
2427
2428 config IA32_EMULATION
2429 bool "IA32 Emulation"
2430 depends on X86_64
2431 select BINFMT_ELF
2432 select COMPAT_BINFMT_ELF
2433 select HAVE_UID16
2434 ---help---
2435 Include code to run legacy 32-bit programs under a
2436 64-bit kernel. You should likely turn this on, unless you're
2437 100% sure that you don't have any 32-bit programs left.
2438
2439 config IA32_AOUT
2440 tristate "IA32 a.out support"
2441 depends on IA32_EMULATION
2442 ---help---
2443 Support old a.out binaries in the 32bit emulation.
2444
2445 config X86_X32
2446 bool "x32 ABI for 64-bit mode"
2447 depends on X86_64 && IA32_EMULATION
2448 ---help---
2449 Include code to run binaries for the x32 native 32-bit ABI
2450 for 64-bit processors. An x32 process gets access to the
2451 full 64-bit register file and wide data path while leaving
2452 pointers at 32 bits for smaller memory footprint.
2453
2454 You will need a recent binutils (2.22 or later) with
2455 elf32_x86_64 support enabled to compile a kernel with this
2456 option set.
2457
2458 config COMPAT
2459 def_bool y
2460 depends on IA32_EMULATION || X86_X32
2461 select ARCH_WANT_OLD_COMPAT_IPC
2462
2463 if COMPAT
2464 config COMPAT_FOR_U64_ALIGNMENT
2465 def_bool y
2466
2467 config SYSVIPC_COMPAT
2468 def_bool y
2469 depends on SYSVIPC
2470
2471 config KEYS_COMPAT
2472 def_bool y
2473 depends on KEYS
2474 endif
2475
2476 endmenu
2477
2478
2479 config HAVE_ATOMIC_IOMAP
2480 def_bool y
2481 depends on X86_32
2482
2483 config X86_DEV_DMA_OPS
2484 bool
2485 depends on X86_64 || STA2X11
2486
2487 config X86_DMA_REMAP
2488 bool
2489 depends on STA2X11
2490
2491 config PMC_ATOM
2492 def_bool y
2493 depends on PCI
2494
2495 source "net/Kconfig"
2496
2497 source "drivers/Kconfig"
2498
2499 source "drivers/firmware/Kconfig"
2500
2501 source "fs/Kconfig"
2502
2503 source "arch/x86/Kconfig.debug"
2504
2505 source "security/Kconfig"
2506
2507 source "crypto/Kconfig"
2508
2509 source "arch/x86/kvm/Kconfig"
2510
2511 source "lib/Kconfig"
This page took 0.080806 seconds and 5 git commands to generate.